Apparatus for producing yarn

ABSTRACT

AN EXTRUSION NOZZLE FOR ASBESTOS DISPERSIONS COMPRISES A SINGLE CONDUIT FEEDING INTO A PLURALITY OF SECONDARY CONDUITS HAVING OUTLET ORIFICES. A CONCAVE OR U-BENT DEFLECTOR IS PROVIDED AT THE JUNCTURE OF ADJACENT SECONDARY CONDUITS AND FACES THE FLOW PATH OF THE DISPERSION IN ORDER TO MINIMIZE FORMATION OF CLOTS AND UNDESIRABLE FIBER ACCUMULATION BETWEEN SECONDARY CONDUITS.

y 11, 1972 J. F. ORZECHOWSKI ETAL 3,676,038

APPARATUS FOR PRODUCING YARN Filed June 26, 1970 nz/eniors:

United States Patent 3,676,038 APPARATUS FOR PRODUCING YARN John F. Orzechowski, Orange, and Thomas W. Haley, Shelton, Conn., assignors to Raybestos-Manhattan, Inc., Bridgeport, Conn.

Filed June 26, 1970, Ser. No. 50,237 Int. Cl. B29f 3/04 U.S. Cl. 425-464 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to improvements in apparatus for the production of yarn from a dispersion containing colloidally dispersed chrysotile asbestos fiber, by extruding said dispersion in the form of a plurality of filaments, subjecting the filaments to contact with a coagulating liquid and then combining them and twisting them to yarn form.

The present invention is particularly adapted to a process which comprises continuously extruding said dispersion in the form of a plurality of filaments at one end of a substantially horizontally disposed elongated receptacle, merging the filaments into a substantially unitary strand and collecting the strands at the opposed end while continuously flowing a coagulating liquid such as aluminum sulfate into said receptacle to thereby envelop and penetrate said filaments and resulting strand and to coagu late it in its passage, followed by separating a portion of the coagulating liquid from the resulting yarn at the opposed end of the receptacle, the composite strands being given some twist into strands while still Wet. The yarn is adapted to be woven into fabric likewise while still wet although it may be permitted to temper in the wet condition to substantially fully penetrate it with the coagulating agent and to permit substantial completion of reaction thereof with the coagulating agent prior to completion of weaving, knitting, braiding, etc. For example, after collecting yarn in a yarn collection device which imparts at least enough twist to hold the filaments together, the yarn package will preferably be at least partially dried and may be cleaned and lubricated prior to further twisting, weaving, etc. In some cases (particularly heavy, multi-ply yarn), we may refine, i.e. dry, clean and/or lubricate the package from the extruder; then, without putting additional twist into the individual packages, combine packages on a twister.

The colloidal asbestos dispersions used in this process described therein are U.S. Pat. 2,626,213 and any of the dispersing agents which are capable of making a good colloidal dispersion and which are capable of being chemically solidified can be used in this process. For example, a fatty acid soap such as ammonium linoleate in proportion of 15-20% based on fiber weight can give a good dispersion and the degree of dispersion is also alfected by the agitating means used in forming the dispersions, a hydrapulper being particularly suitable, it being recognized that although the dispersion is characterized by the extent and nature of the fiber bundles which are opened up to colloidal form, some fiber bundles remain as well as some splints and spicules.

The solids of the dispersion used for the yarn forming process can be between /2 and in water and any 3,676,038 Patented July 11, 1972 one of a number of binders or additives may be added to the colloidal dispersion once formed depending on the properties desired in the final yarn, natural or synthetic latices being generally quite compatible in amounts up to about 30% by weight. In addition a wide variety of other fibers may also be included, either organic such as nylon, rayon, cotton, Teflon, or inorganic such as glass, together with graphite and silica, as set forth in U.S. Pat. 2,772,- 157. Other fillers that can be used are microcrystalline cellulose carboxy methyl cellulose, thermosetting or thermoplastic polymers, starch, carbons, graphites, fluorcarbons, or clay. For example, addition of up to 40% of graphite makes yarn highly suitable for use as packing. Addition of a phenolic or modified phenolic resin together with friction modifying agents can make an end product suitable for industrial and automotive brakes and clutches.

The mixing procedure used for the formation of colloidal asbestos slurry is described in detail in U.S. Pats. 2,626,213 and 2,772,157. The equipment should be of a type which offers a minimum of shearing action which would break down fiber length. A conventional hydrapulper such as that used in paper making, or a vessel equipped with vertical cylindrical mixing bars is adequate.

The dispersion is refined by such means as, for example, are described in U.S. Pats. 2,662,639; 2,685,825; and 3,035,698. The refined dispersion is then fed by means of pumps to reservoirs of adjustable hydraulic head for gravitational flow therefrom into a shallow trough which contains coagulant which is also being flowed.

In order to extrude asbestos dispersions as aforesaid in the form of a plurality of filaments, accepted practice has been to extrude a single filament through a single nozzle, a plurality of filaments thus requiring a plurality of single nozzles. A plurality of single nozzles, say 4, 6, 8, 10, etc., creates a cumbersome handling problem since all nozzles must be placed in close proximity and handled substantially as a unit from which substantially unitary strands are formed. Each single nozzle also requires a single feed tube from an overhead manifold and thus a plurality of nozzles require a plurality of feed tubes and manifold outlets.

It is considered advantageous from a handling aspect to reduce the number of single feed tubes, manifold outlets and unit nozzles by employing a nozzle embodying a single feed inlet and a double orifice outlet. However, it has been discovered, in accordance with the present invention, that because of the nature of the asbestos dispersions (largely colloidal long fibers with some splints, spicules, and bundles) the conventional inverted U-arch of a dual nozzle having a single inlet contributes to the bridging and accumulation of long fibers and non-colloidal splints and bundles. Such accumulations eventually becomes large enough to be washed away from their bridge atop the arch and become part of the main flow pattern of either leg of the dual nozzles. When this clotted accumulation reaches the fine orifice openings of the nozzle, the orifice becomes plugged and results in many breaks during yarn extrusion, a condition which cannot be tolerated in large scale production of textile yarns.

In accordance with the present invention, we have eliminated the aforesaid problem by providing a double orifice extrusion nozzle comprising a U-bent or concave intermediate deflector adapted to inhibit undesirable accumulation at the inlet juncture of the nozzle conduits as will be more fully described in the following specification and accompanying drawing, wherein FIG. 1 shows a diagrammatic fragmentary arrangement 0 of the apparatus of the present invention.

FIG. 2 a fragmentary section on the line 22 of FIG. 1. FIG. 3 is a section on the line 3-3 of FIG. 2 and shows the characteristic dual orifice extrusion nozzle of the present invention.

FIG. 4 is a section of a modified form of extrusion nozzle similar to that shown in FIG. 3, but with two pairs of extrusion nozzles.

Thus, referring to the drawings, a dispersion of chrysotile asbestos fibers is flowed from the trough or manifold through the conduits 11 into the dual nozzles of the present invention generally indicated as 12. The nozzles are engaged on the inclined trough 13 containing a coagulating bath and are held therein by the holder member 14. The dispersion issues in the form of an extrudate from the tips or orifices 15 of the dual nozzles legs '16, 16 wherefrom they are drawn through the coagulating bath by the belt 18 suitably driven over rolls 17, 17 and collected in the damp spinning packages 19 in the form of composite yarn strands 20 whereas some liquid is also removed by any of several standard techniques. Although for illustrative purposes the strands issuing from only a pair of dual nozzles are shown to be combined, the strands issuing from a plurality of dual nozzles may be combined on the trough 13 and before they are twisted in the collecting receptacles 19.

The nozzle 12, is as best shown in FIG. 3, particularly comprises an inlet conduit 21 which is branched and leads to a pair of spaced parallel legs 16 laterally offset to opposite sides of the conduit 21, said legs having tapered ends, with each end having an outlet orifice therein. A crotch 22 is formed at the juncture of branch between the legs 16 and diverts and divides flow of dispersion from the inlet conduit 21 substantially equal between the legs. Thus, a stream of asbestos dispersion fiows through the inlet conduit 21 and is divided substantially centrally at the crotch 22 into two streams that travel through the respective legs 16 and their respective outlet orifices.

As stated previously, a normally shaped convex crotch between the legs 16 causes the longer fibers to accumulate or become hung up thereon, which in turn may cause formation of clots that are too large to pass through the nozzle orifices, thereby undesirably interrupting the continuous operation of the equipment. Unexpectedly, it has been discovered that by providing the crotch 22 with a concave shape relative to flow of dispersant, the problem of fiber accumulation and clogging is eliminated. The curved concave shape at the juncture between the legs causes a flow pattern that continuously flushes the juncture free of the longer fibers, thereby positively eliminating the problem of clot formation.

7 The arrangement of FIG. 4 is similar to that previously described with respect to FIG. 3, but shows an arrangement of more than two nozzles connected to a common inlet 21. Here there are two pairs of nozzles 16, 16 and 16, 16, each pair leading to an inlet 21 with a U-shaped or concave crotch or intermediate portion 22 facing the inlet. The inlets 21 are in turn connected to a common dispersion inlet 23 with an additional concave deflector 24 between the branch inlets 21.

This principle of eliminating sharp resistance to asbestos dispersions provides smooth flow contours and although particularly described herein with respect to asbestos dispersions, can be applied to any conduit juncture (tubing, piping, plumbing, etc.) which is used in the transfer of long fiber asbestos dispersions.

As previously indicated, as the dispersion of asbestos fibers is extruded through the dual nozzles, it is contacted through inlet 23 with the coagulating liquid as indicated in FIG. 2 for the purposes previously explained and such as are described in U.S. 'Pat. No. 3,453,818 and others. The apparatus of the present invention permits economical and consistent spinning of fine-cut yarns such as 300 cut character (cut =yards per pound). On the other hand, individual strands of or 300 cut brought together in the trough 13 or on the rolls 17 and 18 can be processed as one 70 cut end, by way of example. It will also be understood that groups of large numbers of nozzles can be employed for example 50 to 70 nozzles per trough if it is desired to produce a heavier yarn.

Although we have shown and described the preferred embodiment of our invention, it will be understood by those skilled in the art that changes may be made in the details thereof without departing from its scope as com prehended by the following claims.

We claim:

1. In an apparatus for producing strands from an asbestos dispersion wherein the dispersion is formed into filaments and subjected to contact with a coagulating liquid, a double orifice nozzle for forming said dispersion into filaments, said nozzle comprising an inlet, a pair of legs branching from said inlet and having tapered ends with outlet orifices therein, and a concave deflector between said legs facing the flow of dispersion from said outlet to prevent fiber accumulation at the juncture between said legs.

2. In an apparatus for producing strands from an asbestos dispersion wherein the dispersion is formed into filaments and subjected to a coagulating liquid, a multiple orifice nozzle for forming said dispersion into filaments, said nozzle comprising a plurality of legs having outlet orifices at one end thereof, inlet means for feeding said legs with asbestos dispersion, and concave deflector means between adjacent legs facing said inlet means to prevent fiber accumulation between said legs.

3. The apparatus according to claim 2 wherein said nozzle comprises a plurality of pairs of said legs with each pair having a respective inlet and a respective concave deflector means.

4. The apparatus according to claim 3 wherein adjacent inlets are joined at a juncture to a medially disposed common inlet, and wherein said juncture comprises a concave deflector surface facing said common inlet.

References Cited UNITED STATES PATENTS 3,453,818 7/1969 Novak et a1. 5758.89 X 3,196,486 7/1965 Shesler et al. 18l2 DM 2,051,861 8/1936 Jones 18-8 SF 2,217,661 10/ 1940 Anderson 1830 RF X 2,478,005 8/ 1949 Novotny 1830 RD 3,540,077 11/1970 Nakagawa et al. 18-8 SC 3,199,782 8/1965 Shinn 13781.5 X 3,181,546 5/1965 Boothe 137- 815 I SPENCER OVERHOLSER, Primary Examiner M. O. SUTTON, Assistant Examiner 

